Primary cell



Oct. 30, 1934. H. coLLosEus PRIMARY CELL Filed July 14. 1932 lll lfmgarbo ef Hepa/awfzerf mmorgfr'um Patented Oct. 30, 1934 UNITED STATESPRIMARY CELL Heinrich Colloseus, Berlin, Germany Application July 14,1932, Serial No. 622.484

In Germany 3Claim8.

Galvanic dry-cells of the Leclanch type are generally provided with anelectrolyte of ammonium chloride which not only iills the intermediatespace between the zinc anode and the 5 depolarizing material but alsoimpregnat'es the depolarizing material, an addition oi solid ammoniumchloride being sometimes made to the depolarizing material. 'I'hesecells possess a good electrical capacity, but their capacity for beingstored is restricted, this being due to the reet that the zinc isattacked by the ammonium chloride solution even when the cell is atrest. It has also been proposed to use solutions oi magnesium chlorideor manganous chloride or a mixture thereof as the electrolyte, the saidsalts serving, to the exclusion oi ammonium chloride, both forimpregnating the depolarizing material and for iilling the intermediatespace between the latterand the zinc vessel-like anode. Such cells havea good capacity for being stored on account of the zinc being lessrapidly attacked by the said salts. On the other hand they exhibit asomewhat lower electrical capacity, which is chiefly to be ascribed tothe precipitation of hydroxides of magnesium or manganese on orin thedepolarizing material during discharge.

The present invention has for its object to pro- -vide a cell of theLeclanch type which possesses a good capacity for being stored and alarge initial electrical capacity. This is achieved by usingconcentrated magnesium chloride solution, with or without an addition ofmanganous chloride solution, as the electrolyte between the zinc and thedepolarizing material, and by adding ammonium chloride in solid ordissolved form to the depolarizing material. p

The manner in which the invention may be applied is illustrated in theaccompanying drawing, in which Figure 1 is a vertical sectional view ofone form of cell constructed in accordance with the principles of theinvention; and

Figure 2 is a similar view illustrating a modied type ot cell.

In the form o! the invention shown iii Figure 1, a suitable container 10ot vitreous or other inert y material constitutes a support for thecarbon electrode 11, this electrode including a depolarizer and ammoniumchloride. The container is partly filled with a solution oi concentratedmagnesium chloride and is closed by a centrally disposed cap l2 ilttingwithin the carbon electrode and Bupporting a zinc electrode 13.

In the arrangement shown in Figure 2, the outer container 16 is formedof4 zinc .to constitute one o! the electrodes, the construction beingotherwise generally similar to that shown in Figure 1.

It has proved that cells so constituted have not ce only a very goodinitial electrical capacity but also August 8, 1931 (Cl. 13B-103) goodpowers of sustaining storage and of recovery. The danger of theformation of complex zinc compounds which immediately set the cell outoi action is largely avoided, as experience has shown, because diilusionof the sal ammoniac from the depolarizing material into the electrolytetakes place very slowly only and during use oi the cell only. 'Ihisphenomenon is due to the tact that -sal ammoniac is practicallycompletely insoluble in concentrated magnesium chloride solution, sothat there is no tendency at all for the sal ammoniac to pass insubstantial quantities from the depolarizing material into the externalelectrolyte. In this manner it is possible to combine the advantage ofthe sal ammoniac cell in respect oi large initial electrical capacitywith the considerable powers of sustaining storage and of. recovery ofcells whereof the external electrolyte consists essentially o!concentrated magnesium chloride solution.

On the other hand, 'as compared with cells not 4 containing salammoniac, the advantage is also achieved that precipitation othydroxides oi the metals dissolved as salts in the electrolytecannotoccur during the operation of the cell in the presence ot the salammoniac.

Experiments have shown that the electrical capacity of such cells oncontinuous discharge is considerably increased, as compared withotherwise equal magnesium chloride cells not containing sal ammoniac,without the capacity for sustaining storage being materially impaired.

I claimz- El. Primary cell ofthe Leclanche type, comprising electrodes,an electrolyte consisting oi a concentrated solution ot magnesiumchloride, and a depolariaing material containing ammonium chloride.

y 2. Primary cell oi the Leclanch type, comprising electrodes, anelectrolyte consisting of a concentrated solution o! magnesium chloridewith an, addition of manganous chloride solution, and a'. depolarlzingmaterial containing ammonium chloride.

3. Primary dry-cell of the Leclanch-tyiiefcom- "A prising electrodesincluding a zinc anode in the form oi' a vessel, a depolarising materialcontaining an addition of ammonium chloride and an external electrolytefree from ammonium chloride and consisting of a concentrated solution ofmagnesium chloride.

. HEINRICH COILOSEUB.

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